Performance of water distribution networks: Integrated approach

This paper presents the performance dimensions of water distribution networks. In the absence of physical models for pipe deterioration, the evaluation of different performance factors such as maintenance and operating costs, serviceability of water supply, water quality, structural integrity of mains, and system reliability, is analyzed. In particular, predictive models for pipe breakage rates are reviewed, and a method based on the Cox regression for failure time analysis is presented, along with the insightful results of its application to two large urban systems. The assessment of water main conditions requires the combination of a number of data sources, due to the difficulty in inspecting visually buried infrastructure. Descriptive, predictive, and physical analyses are performed on inventory, condition assessment, testing, and maintenance history data. The break causing mechanisms and patterns of failure are reviewed. Factors affecting breakage rates are listed, and their synergistic effect is analyzed. Forces acting on water mains during service are reviewed, along with their contribution to the break event.